Gaibazzi, Nicola

Abstract Introduction Transthoracic echocardiography (TTE) identifies a hypercontractile phenotype (HP) in chronic coronary syndromes (CCS), characterized by elevated resting left ventricular (LV) elastance (force = systolic blood pressure/end-systolic volume). To evaluate the prognostic significance and functional correlates of HP. Methods In a prospective multicentre study, 10 677 patients with CCS underwent resting TTE to assess LV ejection fraction (EF), stroke volume, and force by quantitative volumetric echocardiography. All patients were followed for the endpoint of all-cause mortality. In a subset of 5834 patients, stress echocardiography (exercise or dobutamine) was performed for LV contractile reserve and heart rate reserve. Results Patients were stratified into Force quintiles (Q1–Q5). Patients with hypercontractile phenotype exhibited lower stroke volume at rest (Q5 = 34.8 ± 12.3 vs Q1–Q4 = 57.4 ± 19.1 mL; P < .01) and higher EF at rest (Q5 = 64.8 ± 6.9% vs Q1–Q4 = 58.1 ± 8.7%, P < .01). During a median follow-up of 24 months (interquartile range = 12–40 months), 509 deaths occurred. The exposure-adjusted death rate was lowest in Q3 (3.53–4.51 mmHg/mL; 1.03 per 100 person/years) and higher in Q1 (≤2.62 mmHg/mL, 2.88), Q2 (2.63–3.52 mmHg/mL, 1.86), Q4 (4.52–6.11 mmHg/mL, 1.56), and Q5 (HP, >6.11 mmHg/mL; 1.88; P < .0001 vs Q1 and Q3). Multivariable analysis identified HP (Q5; HR 1.531 vs Q3, 95% CI 1.116–2.099; P = .006) and EF (HR 0.963, 95% CI 0.953–0.972; P < .0001) as independent predictors of death. During exercise or dobutamine stress, HP showed reduced LV contractile reserve (ΔEF: Q5 = 4.3 ± 9.4% vs Q1–Q4 = 7.0 ± 9.3%; P < .001) and blunted heart rate reserve (Q5 = 1.77 ± 0.33 vs Q1–Q4 = 1.85 ± 0.39; P < .01). All patients with force-based LV contractile reserve >4.1 (present in 185, 3.2% of the population) survived. Conclusion Patients with CCS with HP assessed by resting TTE demonstrate higher mortality and multilayered functional impairment, including reduced LV contractile and chronotropic reserves. Hypercontractile phenotype improved the prediction of mortality by EF. A ‘stronger’ heart is, in fact, functionally and prognostically weaker.

Abstract Background Chronotropic incompetence (CI) is a biomarker of cardiac autonomic dysfunction. Aim To assess the risk stratification value of CI during physical or pharmacological stress echocardiography in patients with chronic coronary syndromes. Methods In a prospective, multicenter, international, observational study design, we enrolled 13,445 patients with known or suspected chronic coronary syndromes who underwent stress echo in 19 sites from 10 countries using either exercise (n=2,594), dobutamine (n=2,440), or dipyridamole (n=8,411). Heart rate was automatically measured from the 1-lead ECG in the echo monitor. We considered CI as failure to reach 85% of the maximal predicted (220-age) heart rate for exercise and dobutamine, and heart rate reserve (peak/rest heart rate) <1.22 (<1.17 in permanent atrial fibrillation) for dipyridamole. All-cause death was the outcome measure. Results Heart rate reserve was available in all patients; there was no extra imaging or analysis time, and no intra- and inter-observer variability. CI was observed in 5,045 patients (38%); abnormal regional wall motion abnormality in 1,648 (13%). Over a median follow-up time of 3.5 years, there were 2,426 (18%) deaths. The 10-year mortality was 39% in patients with and 21% in patients without CI (p<0.0001). CI was associated with a significant (p<0.0001) increase in 10-year mortality in all age groups ranging from <54 years to >75 years. In addition, it was associated with increased mortality (p<0.0001) irrespective of β-blocker use (Figure). Cox multivariable analysis revealed that CI was a significant predictor of mortality (HR 1.60, 95% confidence interval 1.47-1.74; p<0.0001) together with age, male sex, diabetes mellitus, ejection fraction, and resting heart rate. Conclusion In patients with chronic coronary syndromes, CI during physical or pharmacological stress is a simple, inexpensive, quantitative, and objective predictor of survival.

Abstract Aims Chronotropic incompetence (CI) is a biomarker of cardiac autonomic dysfunction. The aim of the study is to assess the risk stratification value of CI during exercise or pharmacological stress echocardiography in patients with chronic coronary syndromes. Methods and results In a prospective, multicenter, international, observational study, we enrolled 13 445 patients with known or suspected chronic coronary syndromes who underwent stress echocardiography in 19 clinical sites from 10 countries using either exercise (n = 2594), dobutamine (n = 2440), or dipyridamole (n = 8411). Heart rate was automatically measured from the 1-lead ECG in the echocardiography monitor. We considered CI as failure to reach 85% of the maximal predicted (220-age) heart rate for exercise and dobutamine, and heart rate reserve (peak/rest heart rate) ≤ 1.22 (≤1.17 if in permanent atrial fibrillation) for dipyridamole stress. The primary outcome was all-cause death. CI was observed in 5045 patients (38%) and stress-induced regional wall motion abnormalities in 1648 (13%). Over a median follow-up time of 3.4 years (interquartile range, 1.6–9.1 years), there were 2426 (18%) deaths. The 10-year mortality was 39% in patients with and 21% in patients without CI (P < 0.0001). CI was associated with a significant increase in 10-year mortality in all age groups ranging from ≤54 years to ≥75 years (P < 0.0001). In addition, it was associated with increased mortality (P < 0.0001) irrespective of β-blocker use. Cox multivariable analysis revealed that CI was an independent predictor of mortality (HR: 1.60, 95% confidence interval: 1.47–1.74; P < 0.0001) together with age, male sex, diabetes mellitus, left ventricular ejection fraction, and resting heart rate. Conclusion In patients with chronic coronary syndromes, CI during exercise or pharmacological stress is a simple and objective predictor of survival.

Over the past decade, stress echocardiography has evolved from a test for assessing epicardial artery stenosis to a comprehensive functional test, targeting multiple cardiovascular parameters. The new approach includes several structured steps: (a) evaluating regional wall motion abnormalities to detect epicardial artery stenosis or vasospasm; (b) assessing pulmonary congestion and diastolic function via B-lines with lung ultrasound; (c) gauging preload and contractile reserve with volumetric echocardiography; (d) measuring coronary microvascular reserve using Doppler-based coronary flow velocity in the middistal left anterior descending artery; and (e) determining cardiac sympathetic reserve by tracking heart rate reserve on an ECG. This evolution was supported extensively by the Italian Society of Echocardiography and Cardiovascular Imaging (SIECVI), which played a key role in five areas: (1) developing the initial, curiosity-driven project; (2) disseminating protocols and results at national and international conferences, supporting logistic infrastructure and publication expenses; (3) establishing a digital platform (customized Redcap) for data entry and storage; (4) facilitating patient recruitment across 19 Italian centers; and (5) offering formal endorsement through six presidencies, adding credibility and reach beyond any single institution. The protocol quickly advanced from concept to high-impact publications, earning inclusion in 2024 specialty guidelines. Initially Italian-led, the study now includes 50 centers across 20 countries (e.g. USA and China). Beyond the 50 peer-reviewed papers published in 2016–2024, this study offers a novel, sustainable approach to cardiac stress testing, providing more information at lower costs, with zero radiation and minimal environmental impact. SIECVI’s endorsement was instrumental in amplifying the study’s rigor and outreach.

Myocardial Bridging (MB) is typically a benign congenital coronary anomaly. MB can infrequently result in complications such as myocardial ischemia, arrhythmias, and sudden cardiac death. Recent studies suggest an underlying genetic component for MB involving DES, FBN1, SCN2B, or NOTCH1. The role of percutaneous coronary intervention (PCI) in managing MB, compared to optimal medical therapy (OMT), remains uncertain. Our study used the National Inpatient Sample (NIS) Database to identify patients aged 18 or older with myocardial bridging who were managed with PCI versus medical therapy. We compared the outcomes between both groups including in-hospital mortality, the trend of management of MB and other in-hospital outcomes or complications. Our results showed no statistically significant difference between both subgroups when comparing in-hospital mortality and secondary outcomes of cardiac arrest and the development of an acute kidney injury (AKI). Patients with myocardial bridging treated with PCI had a higher risk of developing cardiogenic shock, requiring LVAD, and requiring the use of intra-aortic balloon pump (IABP) compared to the medical therapy subgroup. Our study suggests the decision to perform PCI in myocardial bridging patients should be individualized such as in patients with refractory symptoms despite medical therapy or those with known high-risk features.

Abstract Background Hypercontractile phenotype of the left ventricle (LV) is an actionable therapeutic target in patients with chronic coronary syndromes (CCS), but its clinical recognition remains elusive. Purpose To assess the clinical variables associated with the hypercontractile phenotype of the LV, identified with supernormal values of an index of LV contractility such as LV force, also known as ventricular elastance. Methods In a prospective, observational, multicenter study, we recruited 5,122 patients (age 65± 11.1 years, 2974 males, 58%) with CCS referred for resting transthoracic echocardiography with technically successful volumetric echocardiography in 17 accredited laboratories. We measured systolic blood pressure (SBP) with a cuff sphygmomanometer. We assessed semi-quantitatively wall motion score index (WMSI), and quantitatively LV end-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF), force (SBP/ESV), stroke volume (SV), arterial elastance (SBP/SV), ventricular-arterial coupling (VAC, as SV/ESV), and cardiac output (CO = SV*heart rate).Univariable and multivariable logistic regression analysis assessed independent factors associated with the highest force sextile. Odds ratios (ORs) with the corresponding 95% confidence interval (CI) were estimated. Results For all the studied patients, EF was 59±11%. Force was 4.51±2.11 mmHg/ml, with reference sextile = 3.50-4.26 mmHg/ml, lowest sextile (Group 1) <2.60 mmHg/ml and highest sextile (Group 6) > 6.36 mmHg/ml. The correlation between the log of EF and the log of Force was significant with linear regression (r = 0.73, p < 0.001). Patients in the highest sextile of force showed lower values of WMSI, SV, EDV, and ESV, and higher values of arterial elastance and VAC (Table). By multivariable logistic regression model, the highest sextile of force was associated with age > 71 years (OR 4.35, 95% CI 3.06-6.18, p < 0.001), female sex (OR 4.48, 95% CI 3.62-5.54, p < 0.001), absence of beta-blocker therapy (OR 1.56, 95% CI 1.27-1.91), rest SBP> 159 mmHg (OR 6.86, 95% CI 5.03-9.35, p < 0.001), high heart rate (OR 1.03, 95% CI 1.02-1.04, p < 0.001), absence of prior MI (OR 1.31, 95% CI 1-1.72, p = 0.049), and higher LV EF at rest (OR 1.24, 95% CI 1.22-1.26, p < 0.001). Conclusions A hypercontractile phenotype of the LV with high force is associated with a small heart, reduced SV, and higher arterial elastance. It was clinically associated with advanced age, female sex, history of hypertension, absence of beta-blocker therapy, and high resting SBP.

Abstract Background Abnormal (<50%) ejection fraction (EF) is a cornerstone of risk stratification and therapy, but also an imperfect proxy of left ventricular (LV) cardiac pump function, better assessed with stroke volume (SV). Aim To assess the value of SV in stratifying risk of patients with abnormal EF. Methods In a prospective, observational, multicenter study, we recruited 746 patients (age 66± 11 years, 536 males, 72%, 359 with previous myocardial infarction, 48%) with chronic coronary syndromes (CCS) and EF <50% referred for resting transthoracic echocardiography with technically successful 2-dimensional volumetric echocardiography in 17 accredited laboratories. We quantitatively assessed LV end-diastolic volume (EDV) and end-systolic volume (ESV) by Simpson’s biplane method. EF (EDV-ESV/EDV) and SV (EDV-ESV) were calculated from LV volumes. The outcome end-point was all-cause death. Results EF was 39±9%, SV 48±20 ml. There were 100 all-cause deaths during a median follow-up of 796 days (interquartile range 420-1286 days). Receiver-operating curve analysis identified SV≤31.4 ml/b as the best cut-off for predicting mortality. At multivariable analysis, after adjustment for age and prior myocardial infarction, EF <40% and SV ≤31.4 ml/b were significantly associated with decreased survival (HR 2.09, 95%, confidence intervals 1.09-4.01, p=0.024). The annual mortality was lowest (3.19%) in the group with mildly reduced (40-49%) EF and normal (>31.4 ml) SV, and highest (8.30%) in patients with both reduced EF and abnormal SV: see figure. Conclusion Patients with CCS and abnormal EF are a prognostically heterogeneous group, and the mortality rate is almost 3-times worse in patients with reduced EF and abnormal SV compared to patients with mildly reduced EF and normal SV. A simple resting volumetric two-dimensional echocardiography can offer an efficient risk stratification, beyond EF, with no extra imaging or analysis time.Figure

Abstract Background Patients with lower extremity peripheral arterial disease (PAD) have a higher risk of cardiovascular events. Stress echocardiography (SE) based on regional wall motion abnormality (RWMA) is imperfect for risk stratification in PAD, but it can be complemented with an assessment of coronary flow velocity reserve (CFVR) in the mid-distal left anterior descending coronary artery. Purpose To assess the value of SE with RWMA and CFVR to predict survival in PAD. Methods In a retrospective analysis of prospectively acquired data in an observational, multicenter study, we recruited 359 patients (age 69±8 years, 240 [67%] males) with PAD referred for dipyridamole SE in 3 accredited laboratories. We assessed RWMA and CFVR (abnormal value <2.0). All patients were followed up for a median of 4.7 (interquartile range: 2.0 to 8.2 years). All-cause death was the outcome end-point. Results The positivity rate was 37/359 (10%) for RWMA and 159/359 (44%) for CFVR. During follow-up, 97 (27%) deaths were registered. At multivariable analysis, inducible RWMA and/or CFVR <2.0 (HR 2.58, 95% CI 1.65-4.04; p<0.0001), age ≥70 years, diabetes, dialysis treatment, and ejection fraction ≤50% were associated with decreased survival. The annual mortality was 7.4% in patients with RWMA and/or CFVR <2.0 and 2.7% in those with no RWMA and CFVR >2.0 (Figure, p<0.0001). Conclusion In patients with PAD, SE shows more than 4-fold higher prevalence of abnormal CFVR compared to RWMA. The prognostic value of CFVR outperforms RWMA, showing the importance of coronary microvascular dysfunction and diffuse, subcritical coronary atherosclerosis in determining the outcome.

Abstract Background Hypercontractile phenotype (HP) of the left ventricle (LV) is an actionable therapeutic target in patients with chronic coronary syndromes (CCS) or heart failure (HF), but its clinical recognition remains difficult. Objectives To assess the clinical variables associated with the HP. Methods In a prospective, observational, multicenter study, we recruited 5,122 patients (age 65 ± 11 years, 2974 males, 58%) with CCS and/or HF with preserved ejection fraction (EF). Systolic blood pressure (SBP) was measured. We assessed wall motion score index (WMSI), LV end-diastolic volume (EDV), end-systolic volume (ESV), EF, force (SBP/ESV), stroke volume (SV), arterial elastance (SBP/SV), and ventricular-arterial coupling (VAC, as SV/ESV). Univariable and multivariable logistic regression analysis assessed independent factors associated with the highest force sextile. Results For all the studied patients, force was 4.51 ± 2.11 mmHg/ml, with the highest sextile (Group 6) > 6.36 mmHg/ml. By multivariable logistic regression model, the highest sextile of force was associated with age > 65 years (OR 1.62, 95% CI 1.36–1.93, p < 0.001), hypertension (OR 1.76, 95% CI 1.40–2.21, p < 0.001), female sex (OR 4.52, 95% CI 3.77–5.42, p < 0.001), absence of beta-blocker therapy (OR 1.41, 95% CI 1.16–1.68), rest SBP ≥ 160 mmHg (OR 2.81, 95% CI 2.21–3.56, p < 0.001), high heart rate (OR 2.08, 95% CI 1.61–2.67, p < 0.001), and absence of prior myocardial infarction (OR 1.34, 95% CI 1.07–1.68, p = 0.012). Patients in the highest sextile of force showed lower values of WMSI, SV, EDV, and ESV, and higher values of arterial elastance and VAC. Conclusions HP of the LV with high force was clinically associated with advanced age, female sex, high resting SBP, and the absence of 𝛽-blocker therapy. By transthoracic echocardiography, HP was associated with a small heart with reduced EDV, reduced SV despite high EF, and higher arterial elastance.